Category: Computers

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[SOLVED] Unable to Connect to ambari-metrics-collector Issues

Posted on by rchapin

I was having some issues with the ambari-metrics family of services on a ‘pseudo-distributed’ cluster that I have installed on my workstation.

The symptoms were:

1.  Ambari indicated the following CRITICAL errors in the Ambari Dashboard under the Ambari Metrics section

Connection failed: [Errno 111] Connection refused to rchapin-wrkstn:6188

2.  After attempting to restart the ambari-metrics-collector via either the Ambari Dashboard or through the commandline (# ambari-metrics-collector [stop|start]) you see the following (similar) messages in the ambari-metrics-collector.log

2016-09-02 12:15:37,505 INFO org.apache.zookeeper.ZooKeeper: Client environment:java.library.path=/usr/lib/ams-hbase/lib/hadoop-native -XX:+UseConcMarkSweepGC -verbose:gc -XX:+PrintGCDetails -XX:+PrintGCDateStam
ps -Xloggc:/var/log/ambari-metrics-collector/collector-gc.log-201609021215
2016-09-02 12:15:37,505 INFO org.apache.zookeeper.ZooKeeper: Client environment:java.io.tmpdir=/tmp
2016-09-02 12:15:37,505 INFO org.apache.zookeeper.ZooKeeper: Client environment:java.compiler=<NA>
2016-09-02 12:15:37,505 INFO org.apache.zookeeper.ZooKeeper: Client environment:os.name=Linux
2016-09-02 12:15:37,505 INFO org.apache.zookeeper.ZooKeeper: Client environment:os.arch=amd64
2016-09-02 12:15:37,505 INFO org.apache.zookeeper.ZooKeeper: Client environment:os.version=3.10.0-327.10.1.el7.x86_64
2016-09-02 12:15:37,505 INFO org.apache.zookeeper.ZooKeeper: Client environment:user.name=ams
2016-09-02 12:15:37,505 INFO org.apache.zookeeper.ZooKeeper: Client environment:user.home=/home/ams
2016-09-02 12:15:37,505 INFO org.apache.zookeeper.ZooKeeper: Client environment:user.dir=/home/ams
2016-09-02 12:15:37,506 INFO org.apache.zookeeper.ZooKeeper: Initiating client connection, connectString=rchapin-wrkstn:2181 sessionTimeout=120000 watcher=hconnection-0x5524cca10x0, quorum=rchapin-wrkstn:2181, b
aseZNode=/ams-hbase-unsecure
2016-09-02 12:15:37,523 INFO org.apache.zookeeper.ClientCnxn: Opening socket connection to server rchapin-wrkstn/172.19.64.2:2181. Will not attempt to authenticate using SASL (unknown error)
2016-09-02 12:15:37,531 INFO org.apache.zookeeper.ClientCnxn: Socket connection established to rchapin-wrkstn/172.19.64.2:2181, initiating session
2016-09-02 12:15:37,536 INFO org.apache.zookeeper.ClientCnxn: Session establishment complete on server rchapin-wrkstn/172.19.64.2:2181, sessionid = 0x155eefbab613617, negotiated timeout = 40000
2016-09-02 12:15:37,582 WARN org.apache.hadoop.hbase.io.util.HeapMemorySizeUtil: hbase.regionserver.global.memstore.upperLimit is deprecated by hbase.regionserver.global.memstore.size
2016-09-02 12:15:38,044 WARN org.apache.hadoop.hdfs.shortcircuit.DomainSocketFactory: The short-circuit local reads feature cannot be used because libhadoop cannot be loaded.
2016-09-02 12:15:38,089 INFO org.apache.phoenix.metrics.Metrics: Initializing metrics system: phoenix
2016-09-02 12:15:38,112 WARN org.apache.hadoop.metrics2.impl.MetricsConfig: Cannot locate configuration: tried hadoop-metrics2-phoenix.properties,hadoop-metrics2.properties
2016-09-02 12:15:38,167 INFO org.apache.hadoop.metrics2.impl.MetricsSystemImpl: Scheduled snapshot period at 10 second(s).
2016-09-02 12:15:38,168 INFO org.apache.hadoop.metrics2.impl.MetricsSystemImpl: phoenix metrics system started
2016-09-02 12:15:38,362 WARN org.apache.hadoop.hbase.io.util.HeapMemorySizeUtil: hbase.regionserver.global.memstore.upperLimit is deprecated by hbase.regionserver.global.memstore.size
2016-09-02 12:15:38,494 WARN org.apache.hadoop.hbase.io.util.HeapMemorySizeUtil: hbase.regionserver.global.memstore.upperLimit is deprecated by hbase.regionserver.global.memstore.size
2016-09-02 12:15:38,627 INFO org.apache.hadoop.hbase.zookeeper.RecoverableZooKeeper: Process identifier=hconnection-0x48d7ad8b connecting to ZooKeeper ensemble=rchapin-wrkstn:2181
2016-09-02 12:15:38,627 INFO org.apache.zookeeper.ZooKeeper: Initiating client connection, connectString=rchapin-wrkstn:2181 sessionTimeout=120000 watcher=hconnection-0x48d7ad8b0x0, quorum=rchapin-wrkstn:2181, b
aseZNode=/ams-hbase-unsecure
2016-09-02 12:15:38,629 INFO org.apache.zookeeper.ClientCnxn: Opening socket connection to server rchapin-wrkstn/172.19.64.2:2181. Will not attempt to authenticate using SASL (unknown error)
2016-09-02 12:15:38,629 INFO org.apache.zookeeper.ClientCnxn: Socket connection established to rchapin-wrkstn/172.19.64.2:2181, initiating session
2016-09-02 12:15:38,633 INFO org.apache.zookeeper.ClientCnxn: Session establishment complete on server rchapin-wrkstn/172.19.64.2:2181, sessionid = 0x155eefbab613618, negotiated timeout = 40000
2016-09-02 12:16:27,001 INFO org.apache.hadoop.hbase.client.RpcRetryingCaller: Call exception, tries=10, retries=35, started=48362 ms ago, cancelled=false, msg=
2016-09-02 12:16:47,033 INFO org.apache.hadoop.hbase.client.RpcRetryingCaller: Call exception, tries=11, retries=35, started=68394 ms ago, cancelled=false, msg=
2016-09-02 12:17:07,148 INFO org.apache.hadoop.hbase.client.RpcRetryingCaller: Call exception, tries=12, retries=35, started=88509 ms ago, cancelled=false, msg=
2016-09-02 12:17:27,257 INFO org.apache.hadoop.hbase.client.RpcRetryingCaller: Call exception, tries=13, retries=35, started=108618 ms ago, cancelled=false, msg=
2016-09-02 12:17:47,276 INFO org.apache.hadoop.hbase.client.RpcRetryingCaller: Call exception, tries=14, retries=35, started=128637 ms ago, cancelled=false, msg=
2016-09-02 12:18:07,333 INFO org.apache.hadoop.hbase.client.RpcRetryingCaller: Call exception, tries=15, retries=35, started=148694 ms ago, cancelled=false, msg=
2016-09-02 12:18:27,397 INFO org.apache.hadoop.hbase.client.RpcRetryingCaller: Call exception, tries=16, retries=35, started=168758 ms ago, cancelled=false, msg=
2016-09-02 12:18:47,410 INFO org.apache.hadoop.hbase.client.RpcRetryingCaller: Call exception, tries=17, retries=35, started=188771 ms ago, cancelled=false, msg=
2016-09-02 12:19:07,555 INFO org.apache.hadoop.hbase.client.RpcRetryingCaller: Call exception, tries=18, retries=35, started=208916 ms ago, cancelled=false, msg=
2016-09-02 12:19:27,732 INFO org.apache.hadoop.hbase.client.RpcRetryingCaller: Call exception, tries=19, retries=35, started=229093 ms ago, cancelled=false, msg=
2016-09-02 12:19:47,923 INFO org.apache.hadoop.hbase.client.RpcRetryingCaller: Call exception, tries=20, retries=35, started=249284 ms ago, cancelled=false, msg=
2016-09-02 12:20:07,950 INFO org.apache.hadoop.hbase.client.RpcRetryingCaller: Call exception, tries=21, retries=35, started=269311 ms ago, cancelled=false, msg=
2016-09-02 12:20:28,051 INFO org.apache.hadoop.hbase.client.RpcRetryingCaller: Call exception, tries=22, retries=35, started=289412 ms ago, cancelled=false, msg=
2016-09-02 12:20:48,230 WARN org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation: Checking master connection
com.google.protobuf.ServiceException: org.apache.hadoop.hbase.exceptions.ConnectionClosingException: Call to rchapin-wrkstn/172.19.64.2:61300 failed on local exception: org.apache.hadoop.hbase.exceptions.Connect
ionClosingException: Connection to rchapin-wrkstn/172.19.64.2:61300 is closing. Call id=46, waitTime=1
        at org.apache.hadoop.hbase.ipc.AbstractRpcClient.callBlockingMethod(AbstractRpcClient.java:223)
        at org.apache.hadoop.hbase.ipc.AbstractRpcClient$BlockingRpcChannelImplementation.callBlockingMethod(AbstractRpcClient.java:287)
        at org.apache.hadoop.hbase.protobuf.generated.MasterProtos$MasterService$BlockingStub.isMasterRunning(MasterProtos.java:55824)
        at org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation$MasterServiceState.isMasterRunning(ConnectionManager.java:1444)
        at org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation.isKeepAliveMasterConnectedAndRunning(ConnectionManager.java:2085)
        at org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation.getKeepAliveMasterService(ConnectionManager.java:1708)
        at org.apache.hadoop.hbase.client.MasterCallable.prepare(MasterCallable.java:38)
        at org.apache.hadoop.hbase.client.RpcRetryingCaller.callWithRetries(RpcRetryingCaller.java:124)
        at org.apache.hadoop.hbase.client.HBaseAdmin.executeCallable(HBaseAdmin.java:4082)
        at org.apache.hadoop.hbase.client.HBaseAdmin.getTableDescriptor(HBaseAdmin.java:527)
        at org.apache.hadoop.hbase.client.HBaseAdmin.getTableDescriptor(HBaseAdmin.java:549)
        at org.apache.phoenix.query.ConnectionQueryServicesImpl.ensureTableCreated(ConnectionQueryServicesImpl.java:810)

3.  You will see WARNings similar to the following in the hbase-ams-regionserver-<hostname>.log file

2016-09-02 12:52:56,589 INFO  [LruBlockCacheStatsExecutor] hfile.LruBlockCache: totalSize=236.59 KB, freeSize=222.74 MB, max=222.98 MB, blockCount=1, accesses=4, hits=3, hitRatio=75.00%, , cachingAccesses=4, cac
hingHits=3, cachingHitsRatio=75.00%, evictions=119, evicted=0, evictedPerRun=0.0
2016-09-02 12:53:52,091 WARN  [timeline] timeline.HadoopTimelineMetricsSink: Unable to send metrics to collector by address:http://rchapin-wrkstn:6188/ws/v1/timeline/metrics
2016-09-02 12:53:52,092 WARN  [timeline] timeline.HadoopTimelineMetricsSink: Unable to send metrics to collector by address:http://rchapin-wrkstn:6188/ws/v1/timeline/metrics
2016-09-02 12:53:52,094 WARN  [timeline] timeline.HadoopTimelineMetricsSink: Unable to send metrics to collector by address:http://rchapin-wrkstn:6188/ws/v1/timeline/metrics
2016-09-02 12:53:52,096 WARN  [timeline] timeline.HadoopTimelineMetricsSink: Unable to send metrics to collector by address:http://rchapin-wrkstn:6188/ws/v1/timeline/metrics
2016-09-02 12:53:52,097 WARN  [timeline] timeline.HadoopTimelineMetricsSink: Unable to send metrics to collector by address:http://rchapin-wrkstn:6188/ws/v1/timeline/metrics
2016-09-02 12:54:52,091 WARN  [timeline] timeline.HadoopTimelineMetricsSink: Unable to send metrics to collector by address:http://rchapin-wrkstn:6188/ws/v1/timeline/metrics
2016-09-02 12:55:52,092 WARN  [timeline] timeline.HadoopTimelineMetricsSink: Unable to send metrics to collector by address:http://rchapin-wrkstn:6188/ws/v1/timeline/metrics
2016-09-02 12:55:52,093 WARN  [timeline] timeline.HadoopTimelineMetricsSink: Unable to send metrics to collector by address:http://rchapin-wrkstn:6188/ws/v1/timeline/metrics

It turned out that the ambari-metrics hbase instance had gotten into an unstable state and that what I needed to do was delete all of the metrics HBase data and restart all of the services.

Making that happen was not as straight-forward as you might imagine.

1. Shutdown all of the AMS (Ambari Metrics System) components.  Do so in the following order:

1. In the Ambari Dashboard, go to the ‘Ambari Metrics’ section and under the ‘Service Actions’ dropdown click ‘Stop’.  If you want, you can click the checkbox to turn on Maintenance Mode to suppress alerts.

2. After the background operation has completed, on the ambari host where you are having issues confirm that all of the AMS components have stopped:

# ambari-metrics-monitor status
psutil build directory is not empty, continuing...
ambari-metrics-monitor currently not running
Usage: /usr/sbin/ambari-metrics-monitor {start|stop|restart|status}

# ambari-metrics-collector status
AMS is running as process 1062.

If either of the processes still report as running issue a stop command.  In my case, I did as follows

# ambari-metrics-collector stop
WARNING: ambari-metrics-collector did not stop gracefully after 5 seconds: Trying to kill with kill -9
ERROR: Unable to kill 1062
Stopping HBase master
no master to stop because no pid file /var/run/ambari-metrics-collector//hbase-root-master.pid

I then confirmed that pid 1062 was indeed dead

# ps -ef | fgrep 1062

2. Delete the AMS HBase data

In the Ambari Dashboard, under the Ambari Metrics section do a search for the hbase.rootdir configuration value.

In my case, I have AMS configured to write to HDFS so the value of this config was: hdfs://rchapin-wrkstn:8020/user/ams/hbase

Then search for the the hbase.tmp.dir configuration value.

In my case, the setting was: /var/lib/ambari-metrics-collector/hbase-tmp

If your hbase.rootdir points to HDFS delete all of the data as follows (as the hdfs user)

[hdfs@rchapin-wrkstn ~]$ hdfs dfs -rm -r -skipTrash /user/ams/hbase/*

If it is on your local file system, simply rm -rf that data, leaving the parent directory

Delete the data in the hbase.tmp.dir (as the root user)

[root@rchapin-wrkstn ~]# rm -rf /var/lib/ambari-metrics-collector/hbase-tmp/*

3. Now restart the AMS services

First, via the Ambari Dashboard, go to the ‘Ambari Metrics’ section and under the ‘Service Actions’ dropdown click ‘Start’.  If you want, you can click the checkbox to turn off Maintenance Mode if you set it when stopping the services.

Then confirm that both the ambari-metrics-monitor and ambari-metrics-collector services have started

[root@rchapin-wrkstn ~]# ambari-metrics-collector status
AMS is running as process 12229.

[root@rchapin-wrkstn ~]# ambari-metrics-monitor status
psutil build directory is not empty, continuing...
Found ambari-metrics-monitor PID: 12916
ambari-metrics-monitor running.
Monitor PID at: /var/run/ambari-metrics-monitor/ambari-metrics-monitor.pid
Monitor out at: /var/log/ambari-metrics-monitor/ambari-metrics-monitor.out

If you see errors in the ambari-metrics-collector.log similar to the following it means that there was a problem re-creating the HBase tables for the metrics-collector and that the AMS HBase tables are missing:

2016-09-02 13:35:36,200 WARN org.apache.hadoop.yarn.server.applicationhistoryservice.metrics.timeline.query.DefaultPhoenixDataSource: Unable to connect to HBase store using Phoenix.
org.apache.phoenix.exception.PhoenixIOException: SYSTEM.CATALOG
        at org.apache.phoenix.util.ServerUtil.parseServerException(ServerUtil.java:108)
        at org.apache.phoenix.query.ConnectionQueryServicesImpl.metaDataCoprocessorExec(ConnectionQueryServicesImpl.java:1039)
        at org.apache.phoenix.query.ConnectionQueryServicesImpl.metaDataCoprocessorExec(ConnectionQueryServicesImpl.java:1002)
        at org.apache.phoenix.query.ConnectionQueryServicesImpl.createTable(ConnectionQueryServicesImpl.java:1208)
        at org.apache.phoenix.query.DelegateConnectionQueryServices.createTable(DelegateConnectionQueryServices.java:112)
        at org.apache.phoenix.schema.MetaDataClient.createTableInternal(MetaDataClient.java:1974)
....
Caused by: org.apache.hadoop.hbase.TableNotFoundException: SYSTEM.CATALOG
        at org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation.locateRegionInMeta(ConnectionManager.java:1264)
        at org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation.locateRegion(ConnectionManager.java:1162)
        at org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation.locateRegion(ConnectionManager.java:1146)
        at org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation.locateRegion(ConnectionManager.java:1103)

To fix, delete the node in zookeeper, and restart the AMS services

Check the current value of the Ambari Metrics config: zookeeper.znode.parent.  In my case the value was: /ams-hbase-unsecure

Stop all of the AMS services as described above.

Then, using the zookeeper cli connect to your zookeeper cluster and delete the zookeeper node

1. Start up the zookeeper client

# /usr/hdp/current/zookeeper-client/bin/zkCli.sh

2. Connect to the zookeeper cluster, and list the root nodes for the cluster

[zk: localhost:2181(CONNECTED) 1] connect 127.0.0.1:2181
[zk: 127.0.0.1:2181(CONNECTED) 2] ls /
[hiveserver2, zookeeper, hbase-unsecure, ams-hbase-unsecure, rmstore]

3. Delete the ams-hbase-unsecure node

[zk: 127.0.0.1:2181(CONNECTED) 3] rmr /ams-hbase-unsecure

    4. Restart the AMS services as described above and then confirm that the ams-hbase-unsecure node was recreated in zookeeper.

[zk: 127.0.0.1:2181(CONNECTED) 4] ls /
[hiveserver2, zookeeper, hbase-unsecure, ams-hbase-unsecure, rmstore]

    

Dynamically Instantiating Classes in Python

Posted on by rchapin

A common design pattern is to define a class or list of classeses in configuration such that at runtime the classes can be dynamically instantiated.

I’ve done this before in many other languages and had need to do so today in Python (2.7.11)

It seems as though the clean way to do so is by using the Pyton importlib module.  By using it, it enables you to cleanly dynamically import sub modules

Following is an example:

import importlib

klass_1_module = 'some.module.name'
klass_1_classname = 'KlassNameOne'

klass_2_module = 'klass2module'
klass_2_classname = 'KlassNameOne'

Klass1 = getattr(importlib.import_module(klass_1_module), klass_1_classname)
klass1_instance = Klass1()

Klass2 = getattr(importlib.import_module(klass_2_module), klass_2_classname)
klass2_instance = Klass1('some_arg')

Java PowerMock Could not reconfigure JMX java.lang.LinkageError Solution

Posted on by rchapin

If you are using Mockito and PowerMock to build mocks for your Java tests and you run into the following error:

2016-05-05 17:31:20,204 main ERROR Could not reconfigure JMX java.lang.LinkageError: loader constraint violation: loader (instance of org/powermock/core/classloader/MockClassLoader) previously initiated loading for a different type with name "javax/management/MBeanServer"
        at java.lang.ClassLoader.defineClass1(Native Method)
        at java.lang.ClassLoader.defineClass(ClassLoader.java:760)
        at org.powermock.core.classloader.MockClassLoader.loadUnmockedClass(MockClassLoader.java:238)
        at org.powermock.core.classloader.MockClassLoader.loadModifiedClass(MockClassLoader.java:182)
        at org.powermock.core.classloader.DeferSupportingClassLoader.loadClass(DeferSupportingClassLoader.java:70)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:357)

Simply add the following as a class level annotation:

@PowerMockIgnore( {"javax.management.*"} )

Blacklisting Kernel Modules

Posted on by rchapin

Following is a walkthrough on how to blacklist a kernel module.  The specific example is blacklisting the nouveau driver so that I can install the OEM Nvidia driver.

1. First, blacklist the nouveau driver: Add a line to the textfile /etc/modprobe.d/nouveau-blacklist.conf that contains they keyword ‘blacklist’ and the name of the driver

blacklist nouveau

2. Rebuild the initramfs image file.  First, backup existing initramfs

mv initramfs-3.10.0-327.18.2.el7.x86_64.img initramfs-3.10.0-327.18.2.el7.x86_64.img_2016-06-09.bak

Build new initramfs

dracut -v /boot/initramfs-$(uname -r).img $(uname -r)

3. Reboot the system and confirm that the driver in question is not loaded.

lsmod | fgrep nouveau

How to Return Hive Query Results Similary to MySQL \G in One Vertical Column

Posted on by rchapin

When trying to look at data in a database with really wide rows even just selecting 1 row to see the data is nearly impossible to understand when the single row wraps 7 or 8 times.

MySQL offers the ‘\G’ option to display the output in a single column.

The corresponding method in Hive is to execute the following set command:

> !set outputformat vertical
> SELECT something FROM some table;

How to Configure a User Account in Active Directory So that the Password Never Expires

Posted on by rchapin

Using ADSI Edit, navigate to the user in question.  Right-click on the user and select Properties.

Then, scroll down to the ‘userAccountControl’ property and click the Edit button.

Enter 66048 into the field and then click ‘OK’ and then ‘Apply’.

After closing the edit window, scroll to the right to confirm that the value indicates the following

'0x10200 = (NORMAL_ACCOUNT|DONT_EXPIRE_PASSWORD)'

Using netcat to Mock a RESTful Webservice that Returns JSON

Posted on by rchapin

Let’s say that you are working on a part of a project that needs to consume some JSON data from a forthcoming HTTP service.  That sub-system is being developed by one of your colleagues and is not yet ready for you to stand-up to develop against.

You can use netcat to mock the webservice and return some static JSON data for which you can develop and test against with a simple one-liner.

First, put together your JSON in a file, ‘my.json’ and then run the following command in a terminal:

while true; do echo -e "HTTP/1.1 200 OK\r\n\r\n$(cat my.json)" | nc -l 9998; done

An hitting http://localhost:9998 will return your test JSON data.

How to Use Credentials That Contain Special Characters with curl

Posted on by rchapin

In order to execute curl commands to endpoints with passwords that contain special characters, the cleanest way that I have found to do so is to Base64 encode the authentication string for curl and then pass an Authorization request header along with the request.

In this example the credentials are uid ‘rchapin’ and passwd ‘abc123!@#’.  Normally we would pass this to curl as follows:

$ curl -u rchapin:abc123!@# -X GET https://some-endpoint:443

However, this will not work and the password will need to be sent in some other fashion other than ASCII.

Following are the steps to pass the credentials as Base64:

1. Using your favorite Base64 encoder, generate and ASCII string of the entire ‘username:password’ string that you would normally pass with the -u option for curl

rchapin:abc123!@# converted = cmNoYXBpbjphYmMxMjMhQCM=

2. Now modify the curl command as follows:

$ curl -H "Authorization: Basic cmNoYXBpbjphYmMxMjMhQCM=" -X GET https://some-endpoint:443

Solution for MySQL ERROR 1396 (HY000): Operation CREATE USER failed for

Posted on by rchapin

This indicates that the user already exists, or did exist but that all of the data for that user has not been deleted.

As the mysql root user:

REVOKE ALL PRIVILEGES, GRANT OPTION FROM 'user'@'hostname';
DROP USER 'user'@'hostname'

Then re-try creating the user.

How to Configure a Linux Client for Active Directory Authentication

Posted on by rchapin

I am currently working on setting up multiple environments for a new project (DEV, QA, and PROD) and will be integrating all of the servers to an Active Directory Domain Controller for user management.

Following are notes from when I configured a Fedora Core 18 laptop to integrate with an AD server.  It is likely things have changed some from then and I will update this as required for a current version of RHEL7/CentOS 7.

Install the following packages

yum install sssd-tools adcli realmd

sssd will not yet have the /etc/sssd/sssd.conf file installed until you join a domain (see below) so do not try to configure it.

Disable selinux. Perhaps selinux can be re-enabled after joining and configuration?

Search for a realm

realm discover -v
 * Looking up our DHCP domain
 * Discovering for DHCP domain: somedomain.com
 * Searching for kerberos SRV records for domain: _kerberos._udp.somedomain.com
 * Searching for MSDCS SRV records on domain: _kerberos._tcp.dc._msdcs.somedomain.com
 * server1.somedomain.com:88 server2.somedomain.com:88 server3.somedomain.com:88
 * Found kerberos DNS records for: somedomain.com
 * Found AD style DNS records for: somedomain.com
 * Successfully discovered: somedomain.com
somedomain.com
  type: kerberos
  realm-name: SOMEDOMAIN.COM
  domain-name: somedomain.com
  configured: kerberos-member
  server-software: active-directory
  client-software: sssd
  required-package: sssd-tools
  required-package: sssd
  required-package: adcli
  required-package: samba-common
  login-formats: SOMEDOMAIN\%U
  login-policy: allow-any-login

Joined the domain

realm join -U admin --verbose somedomain.com

Allow all users from a given domain to login

realm permit --realm somedomain.com --all

Add the home directory paths

mkdir /home/SOMEDOMAIN

 Start and enable sssd

systemctl enable sssd && systemctl start sssd

Log out from the local user account and then log in as a user in the domain:
    . uid: SOMEDOMAIN\uid
    . This will log you in as that user and create a home account in /home/SOMEDOMAIN/uid

© 2005 Ryan Chapin